Requires Mg2+. This enzyme, isolated from the bacterium Microbacterium 5-2b, participates in a carminate degradation pathway. Following the activity of EC 184.108.40.206, C-glycoside oxidase, it cleaves the C---C bond in 3'-dehydrocarminate. The sugar moiety is released lacking a hydroxyl at position 1, and containing a double bond between C-1 and C-2. The enzyme shows weak activity with other 3'-dehydro-C-glucosides.